Starter Joint with Internal Upset for Expandable Liner
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Solution Overview
Problem
Existing wellbore expansion systems lack a starter joint to securely lock the expansion string during transport and deployment, leading to premature expansion and difficulties in introducing tubular elements through existing casings, especially due to weight and torque transmission issues.
Innovation Solution
An assembly featuring a starter section with an internal upset and support means on the expansion string to transmit weight and torque, preventing premature expansion by allowing upward movement of the expander to radially expand the tubular element while maintaining stability during descent.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the tubular element is suspended on an expansion string during running-in, then the tubular element can be lowered into the wellbore, but the weight of the tubular element may cause it to slip downward relative to the expansion string and result in premature expansion
Solution Approach 1:
A starter joint with an internal upset is attached to the lower end of the tubular element before running-in. This starter joint creates a mechanical interlock with the expansion string that preliminarily secures the relative position, preventing the tubular element from slipping downward during the lowering operation before the expansion string is fully deployed
Solution Approach 2:
The starter joint acts as an intermediary component between the tubular element and the expansion string. It provides a mechanical interface that transfers and distributes the weight and forces, preventing direct slippage between the tubular element and expansion string while enabling controlled expansion when needed
2Device complexity
If the expansion string is not locked to the tubular element during transport and make-up, then the assembly is simpler, but the expansion string cannot reliably transmit weight and torque during deployment
Solution Approach 1:
The starter joint with its internal upset is pre-attached to the tubular element during manufacturing or assembly operations on the rig floor. This preliminary action creates a permanent mechanical lock that will reliably transmit weight and torque during the subsequent running-in and expansion operations, eliminating the need for complex locking mechanisms during deployment
Solution Approach 2:
The tubular element assembly is segmented into distinct functional components: the tubular element itself, the starter joint with internal upset, and the expansion string. This segmentation allows each component to be optimized for its specific function while maintaining a relatively simple overall assembly structure
3Stability of the object's composition
If subsequent liner sections are expanded to the same diameter as the previous section, then the wellbore inner diameter remains substantially constant, but the risk of premature expansion increases during lowering
Solution Approach 1:
The starter joint with internal upset is installed as a preliminary measure before lowering the expandable liner into the wellbore. This preliminary mechanical interlock ensures that the liner cannot prematurely expand during the lowering operation, maintaining reliability while enabling the desired constant diameter wellbore configuration
Solution Approach 2:
The starter joint creates a preliminary anti-action force that counteracts the tendency of the liner to expand prematurely under its own weight during lowering. This preliminary counter-force ensures that expansion only occurs when intentionally triggered by the expansion string at the desired location and time
Data Source
AI summary
In an assembly for lowering and expanding a tubular element in a borehole on an expansion string, at least part of the weight of the tubular element is transmitted to the expansion string via an internal upset and a support protruding from an outer surface of the expansion string below the internal upset.